The “48” mini-mill

A short post highlighting a small set of papers (currently five) that all share some interesting features. As before, these might all have been produced by the same paper-writing entity, a so-called “paper mill”.

Similar to the Tadpole paper set, where all Western blot panels showed the same background noise, most wound healing assay photos in this mini-mill share the same microscope irregularities. And all of them describe a group of 48 patients.

The papers are from different groups of authors at different hospitals, describing different cancer types. Yet, they share several similar features.

All five papers describe a group of 48 patients. Sometimes they have lung cancer, or nasopharyngeal cancer, or prostate cancer. But always 48 patients.
All five papers describe the same set of GAPDH primers. One of them (the reverse primer) does not appear to match the GAPDH mRNA sequence.
Figures 1 of all five papers show black bar graphs with error bars and a Kaplan-Meier curve with a blue and a red line
Two papers (XX Ma et al. and JL Xu et al.) share nearly identical positive correlation curves
All five papers show photos of wound healing (scratch) assays with the same background, suggesting they were all taken with the same microscope.

Here is the set of papers:

J.-L. Xu, T. Hua, J. Ding, Y. Fan, Z.-J. Liu, J.-W. Lian – FOXF2 aggravates the progression of non-small cell lung cancer through targeting lncRNA H19 to downregulate PTEN – Eur Rev Med Pharmacol Sci 2019; 23 (24): 10796-10802 – DOI: 10.26355/eurrev_201912_19782 – Department of Oncology, Xi’an Chest Hospital, Xi’an, China [PubPeer comment]
Q.-Z. Meng, C.-H. Cong, X.-J. Li, F. Zhu, X. Zhao, F.-W. Chen – METTL3 promotes the progression of nasopharyngeal carcinoma through mediating M6A modification of EZH2 – Eur Rev Med Pharmacol Sci 2020; 24 (8): 4328-4336 – DOI: 10.26355/eurrev_202004_21014 – Department of Head and Neck Surgery, Linyi Cancer Hospital, Linyi, China [PubPeer comment]
T. Chen, J. Li, M.-H. Zhou, L.-J. Xu, T.-C. Pan – IL-6 stimulates lncRNA ZEB2-AS1 to aggravate the progression of non-small cell lung cancer through activating STAT1 – Eur Rev Med Pharmacol Sci 2020; 24 (7): 3734-3740 – DOI: 10.26355/eurrev_202004_20837 – Department of Cardiovascular Surgery, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China [PubPeer comment]
T. Zhou, J.-J. Fang, Y.-X. Zhou, Z.-P. Li, L. Jiang, W.-W. Han, Z.-H. Zhu – Long non-coding RNA ANCR promotes progression of NSCLC by inhibiting E-Ca expression – Eur Rev Med Pharmacol Sci 2020; 24 (3): 1250-1257 – DOI: 10.26355/eurrev_202002_20178 – Department of Respiratory Medicine, Zhoushan Hospital of Zhejiang University, Zhoushan, China [PubPeer comment]
X.-X. Ma, Z.-G. Cao, S.-L. Zhao – m6A methyltransferase METTL3 promotes the progression of prostate cancer via m6A-modified LEF1 – Eur Rev Med Pharmacol Sci 2020; 24 (7): 3565-3571 – DOI: 10.26355/eurrev_202004_20817 – Department of Urology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China [PubPeer comment]

Here is a comparison of the Figures 1 from these papers. The very similar looking correlation curves of XX Ma et al. and JL Xu et al. have been highlighted with red boxes.

Here is a comparison of the wound healing assay photos, with similar background spots highlighted in green and yellow boxes. Contrast enhanced. These appear to be irregularities in the microscope, which by itself is not a problem. But it is unexpected to see the same similarities in photos obtained across different laboratories.